Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• cyclic (alkyl)(amino) or mesoionic carbenes (CAACs or MICs) onto carbon disulfide. Nine novel compounds were isolated and fully characterized by 1H and 13C NMR, FTIR, and HRMS techniques. Moreover, the molecular structures of two CAAC·CS2 and two MIC·CS2 betaines were determined by X-ray diffraction

• . Crystallography Crystals of CAAC·CS2 zwitterions 4a and 4c suitable for X-ray diffraction (XRD) analysis were grown by slow diffusion of cyclohexane in a THF solution at 6 °C. Their molecular structures are depicted in Figure 3. The orange-red needles of compound 4a belonged to the trigonal space group, while

• betaines were determined by X-ray diffraction analysis. The various analytical data recorded for all these compounds were compared with those reported previously for related NHC·CS2 zwitterions derived from imidazolinium or (benz)imidazolium salts. Due to the absence of electronic communication between the

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• pulling away and pulling in processes. In particular, we analyzed the X-ray conformation (PDB ID: 1BFC) based MD trajectory and windows 5 and 10 and windows 6, 8, 10 in the forward and reverse processes, respectively (Figure 7). Interestingly, in all these windows with more favorable binding energies

• , particular three positively charged residues, R101, K106, and K116, maintained strong H-bonds that have been also established in the X-ray structure-based MD simulation [51]. Some of these residues are absent as the most contributing to H-bonding in the less stable complexes (both last windows of the pulling

• away and pulling in processes). At the same time, the essential difference between the H-bonding pattern observed in the unrestrained MD simulation of the X-ray structure is that there were several non-charged residues (N8, A17, Y84) among the top residues contributing to H-bonds, while almost

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• yields. The chemical structures of the spiro compounds 7a–n were established by various spectroscopy methods. In addition, the single crystal structure of compound 7a was also determined by X-ray diffraction (Figure 1). As can be seen from Figure 1, both the C–C and C–N double bonds are part of the

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• and iPrOH, resulting in the formation of compound 37 in 49% yield. In the final step, Ir-catalyzed cycloaddition reaction with diphenylacetylene (tolane) led to PAH 38 in 47% yield. According to the X-ray analysis results, it is evident that the structure of compound 38 is far from planarity, and the

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• and visible–near infrared spectroscopy. The reaction of La@C2v-C82 with alkyl halides using the same conditions showed no consumption of La@C2v-C82, indicating that the reactivity of La@C2v-C82 toward alkyl halides was effectively increased by one-electron reduction. Single-crystal X-ray diffraction

• @C2v-C82(CHClC6H3Cl2) [19] and La@C2v-C82(CBr(CO2Et)2) [23], by single-crystal X-ray diffraction (SC-XRD) analysis. Based on the similarity in the absorption spectra of La@C2v-C82(CHClC6H3Cl2), the addition site of 3a–c was expected to be at the C10 (for the numbering of carbon atoms in La@C2v-C82; see

• , assuming that La@C2v-C82 and the monoadducts have the same absorption coefficients. X-ray crystallography Black crystalline rods of 3a were obtained using the liquid–liquid bilayer diffusion method with 3a in a CS2 solution and an n-hexane solution in a glass tube (⌀ = 7 mm) at room temperature. The SC-XRD

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• conversion of the NH-heterocycle, and the yields of target compounds 6n and 6o were slightly diminished. The single-crystal X-ray data verified the structure of product 6n. The data obtained on the regioselectivity of reactions with benzotriazoles are in agreement with those previously reported in the

• %); bNMR yield; cstructure confirmed by single-crystal X-ray data; dcalculated yield based on incomplete conversion of NH-substrate. Examples of N-deprotection of α-modified glutarimides 1. Preparation of NH2-containing derivative 10 via reduction of 6n. Supporting Information Deposition number 2298240

• : General experimental information, X-ray crystallographic data, synthetic procedures, analytical data and NMR spectra for the reported compounds. Acknowledgements We thank the Research Center for Magnetic Resonance, the Center for Chemical Analysis and Materials Research, and the Center for X-ray

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• concentrations of 1a. Photocatalytic CO2 reduction tests with different concentrations of HFIP.a Supporting Information Additional information regarding the instrumentation, structural analyses, and X-ray structures is provided. Crystal structures were deposited in the Cambridge Crystallographic Data Centre

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• 1758 cm−1 (C=O). X-ray diffraction (XRD) measurements of 1 and 2 are shown in Figure 2. The Miller indices indicate the Colhex and Colrect character of the mesophases [31]. Despite crystallization of 2, the Colrect order is partially preserved at room temperature. The Colhex lattice parameter (a

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• were used to calculate the percentage decrease in concentration of the compound with respect to the first reading and data were processed using the OriginPro 21 software. X-ray diffraction Single crystals of hdz-CH3 and hdz-NO2 suitable for X-ray diffraction were obtained from the slow evaporation of

• the syntheses’ mother liquors. They were analyzed in a D8-Venture Bruker diffractometer equipped with Mo Κα X-ray source at 293 K. Diffraction images were collected with a Photon III area detector and the frames were integrated with the Bruker SAINT software using a narrow-frame algorithm [51

• the Federal Fluminense University (LDRX-UFF: http://ldrx.sites.uff.br/) for the X-ray diffraction facilities. Funding SPM, DSC and NAR thank the scientific Brazilian funding agency CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) - 304105/2021-0, 150898/2022-3 and 306866/2021-8

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• the R2 group. The stereochemistry of products 10 and 11 was confirmed by X-ray crystal structure and the 1H NMR analysis of both the major and minor diastereomers [69]. The first cycloaddition gives adducts 12 and 12’ as a diastereomeric mixture. At the second cycloaddition, both major and minor

• symmetry. The stereochemistry of the products was confirmed by X-ray crystal structure and NMR analysis. The reaction mechanism shown in Scheme 11 suggests that a semi-stabilized AMY 16 generated from the reaction of glycine and arylaldehydes undergoes a [3 + 2] cycloaddition with 14a via the favorable

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• derivatives (including 1bH, the structure of which has previously been reported, but with somewhat lower precision than in the present work [34]), and three salts of 1+ cations using single-crystal X-ray diffraction. Here, we briefly discuss some of the more interesting structural findings; a more detailed

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• ligands. Compound 19-Co (structure not shown) retained the cobalt(II) oxidation state with a water molecule within the cleft. The XRD analysis of the structures of 19-Co and 18b-Co exhibited Pacman conformation. The X-ray molecular structure of 19-Co provided further insights, showing a square-planar

• geometry with the cobalt(II) positioned slightly above the N4 donor plane. The X-ray structure of 18b-Co exhibited a similar Pacman motif as its palladium analogue, with the cobalt(II) cation residing in a square-planar environment. The exploitation of a similar synthetic methodology allowed for preparing

• flexibility of macrocyclic ligands, as demonstrated by X-ray molecular structures. The helicates consisted of two metal centres, namely cobalt, manganese, or iron, each coordinated by two nitrogens and oxygen donors of the ligand. The metal centres adopted distorted octahedral geometries with slight

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

• Aaron H. Shoemaker,
• Elizabeth A. Foker,
• Elena P. Uttaro,
• Sarah K. Beitel and
• Daniel R. Griffith

Beilstein J. Org. Chem. 2023, 19, 1615–1619, doi:10.3762/bjoc.19.118

• best among those screened, yields remained modest (44%). X-ray analysis provided confirmation of the structure of bicycle 8 (CCDC No. 2263675). While searching for methods to improve the yield of our desired azabicycle, we came across the observation of Andrade and Kokkonda that vinylic halides with

• of X-ray structure data for compound 8. Supporting Information File 11: Copies of 1H and 13C NMR spectra of all purified novel compounds. Supporting Information File 12: Chrystallographic information file (cif) of X-ray structure for compound 8. Acknowledgements We acknowledge Prof. Dasan Thamattoor

• (Colby College) and Prof. Bruce Foxman (Brandeis University) for X-ray analysis of compound 8. High-resolution mass spectra were obtained at the Mass Spectrometry Lab at the University of Illinois. Funding We thank the donors of the American Chemical Society Petroleum Research Fund (Grant No. 59202-UNI1

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• still unclear, and so we grew high quality crystals of B4 and B6 to unambiguously determine the structure through X-ray crystallography, which showed the oxidation was in fact occurring at position-13 (Figure 2). A potential mechanistic explanation for the formation of this oxidation byproduct can be

• structures of two unexpected oxidized berberine variants were elucidated through X-ray crystallography. Overall, the berberine series showed much greater promise, with several variants displaying heightened antibacterial activity compared to original berberine. Meanwhile the chelerythrine variants were

• with associated standard error (n = 5). Vancomycin, streptomycin, and/or fluconazole were used as positive controls, and solvents were used as negative controls and showed no zones of inhibition. X-ray crystal structures of the oxidation byproducts a) B4 (CCDC 2271457) and b) B6 (CCDC 2271458; one

Unraveling the role of prenyl side-chain interactions in stabilizing the secondary carbocation in the biosynthesis of variexenol B

• Moe Nakano,
• Rintaro Gemma and
• Hajime Sato

Beilstein J. Org. Chem. 2023, 19, 1503–1510, doi:10.3762/bjoc.19.107

• computational models in the future. Furthermore, future research is expected to determine whether there is space in the enzyme active site for these prenyl side chains to fold and approach the reaction center, as seen in X-ray crystallographic analysis. Experimental All calculations were carried out using the

Cyclization of 1-aryl-4,4,4-trichlorobut-2-en-1-ones into 3-trichloromethylindan-1-ones in triflic acid

• Vladislav A. Sokolov,
• Andrei A. Golushko,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2023, 19, 1460–1470, doi:10.3762/bjoc.19.105

• , exact structures of compounds 1g,h,s,t,v were confirmed by X-ray analysis (see Supporting Information File 1). The hydroxy ketones 1 were used as precursors for the synthesis of 1-aryl-4,4,4-trichlorobut-2-en-1-ones (CCl3-enones) 2 by dehydration of compounds 1 with p-toluenesulfonic acid monohydrate at

• by X-ray analysis (see Supporting Information File 1). Both, hydroxy ketone 1 and the corresponding enone 2, can be converted into the same indanone 3 in comparable yields; see pairs of reactions for 1a and 2a (indanone 3a), 1d and 2d (indanone 3d), 1i and 3i (indanone 3i), and 1n and 3n (indanone 3n

• spectra. Acknowledgements Spectral studies were performed at the Center for Magnetic Resonance, Center for Chemical Analysis and Materials Research, and the Research Center for X-ray Diffraction Studies of Saint Petersburg State University, Saint Petersburg, Russia. Funding This work was supported by the

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• , Cazin and co-workers reported the synthesis of Cu(I) complexes 61, 63, and 65 of the so-called ‘abnormal’ NHCs (Scheme 21) [35]. Thus, the conventional heating method as well as microwave irradiation methods were employed. The structures of the synthesized complexes were confirmed by X-ray analysis

• consecutive treatment of the corresponding azolium salts with silver oxide and copper chloride (Scheme 25). The X-ray structure of one of the complexes, [(TPrXyl)CuCl], revealed that the NHC–Cu–Cl bond angle is 177.8°, indicating almost linearity. These synthesized complexes were also used as efficient

• used 1,3-diisopropylbenzimidazol-2-ylidene (iPr2-bimy) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) (Scheme 28) [40]. The structures of all the synthesized complexes were confirmed by X-ray crystallography. A similar strategy was followed for stabilizing copper- and silver tert

Visible-light-induced nickel-catalyzed α-hydroxytrifluoroethylation of alkyl carboxylic acids: Access to trifluoromethyl alkyl acyloins

• Feng Chen,
• Xiu-Hua Xu,
• Zeng-Hao Chen,
• Yue Chen and
• Feng-Ling Qing

Beilstein J. Org. Chem. 2023, 19, 1372–1378, doi:10.3762/bjoc.19.98

• sterically hindered tertiary carboxylic acids were unfortunately not compatible with the reaction conditions. The structures of products 3a and 3s were unambiguously confirmed by single-crystal X-ray diffraction. Notably, the reaction of 1a could be easily scaled up to 1.0 mmol scale, affording 3a in a

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• isomeric mixture of 4BGIPN. This is expectedly higher than the analogous Tg of 176 °C for the 4CzIPN material [13] due to a lower molecular mass of the latter (Figure S1, Supporting Information File 1). Single crystals for X-ray diffraction study were obtained by slow layer diffusion of hexanes into

• the pure product as a yellow powder in 70% yield (450 mg, 474 μmol). Single crystals suitable for X-ray diffraction were grown by layering a concentrated solution in DCM with hexane which was left for slow evaporation. 1H NMR (700 MHz, DMSO-d6) δ 8.46–8.35 (m), 8.23–8.22 (m), 8.16–8.06 (m), 7.94–6.86

• ppm; Anal. calcd. for C60H32N14 (948.29): C, 75.94; H, 3.40; N, 20.66; found: C, 75.59; H, 3.54; N, 20.28; HRESIMS m/z: [M + Na]+ calcd. for C60H32N14Na, 971.2827; found, 971.2854. X-ray crystallography Crystals suitable for X-ray diffraction study were obtained by slow layer diffusion of hexanes

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• effect. The single crystal structure of compound 3a was determined by X-ray crystallographic diffraction (Figure 1). From Figure 1 it can be seen that the two scaffolds of oxindole at neighboring positions are in trans-configuration. The ethoxycarbonyl group is also in trans-position to the carbonyl

• different reactivity to that of the adducts of 3-ethoxycarbonylmethyleneoxindoles. For confirming the chemical structures of dispirooxindoles 4a–i, the single crystal structure of compound 4a was determined by X-ray diffraction (Figure 2). In Figure 2, the two oxindole scaffolds are in trans-position. The

Cyanothioacetamides as a synthetic platform for the synthesis of aminopyrazole derivatives

• Valeriy O. Filimonov,
• Alexandra I. Topchiy,
• Vladimir G. Ilkin,
• Tetyana V. Beryozkina and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2023, 19, 1191–1197, doi:10.3762/bjoc.19.87

• pyrazoles has been thus synthesized. The structure of the reaction products was studied using NMR spectroscopy and mass spectrometry and confirmed by X-ray diffraction analysis. Keywords: aminopyrazoles; 2-cyanothioacetamides; enamines; hydrazines; Introduction Compounds containing a pyrazole cycle

• group during the reaction. The structures of compounds 5a–e were confirmed by 1H and 13C NMR spectroscopy and HRMS, as well as X-ray diffraction analysis of a single crystal of compound 5b. The involvement of arylhydrazines 3b,c in the reaction with enamines 2a–d similarly leads to the formation of 1

• upon addition of hydrochloric acid. This is probably due to the protonation of the dimethylamino moiety or/and that dimethylamine hydrochloride is a better leaving group than the free base. The structures of compounds 6a–f were confirmed by 1H and 13C NMR spectroscopy and HRMS, as well as X-ray

Exploring the role of halogen bonding in iodonium ylides: insights into unexpected reactivity and reaction control

• Carlee A. Montgomery and
• Graham K. Murphy

Beilstein J. Org. Chem. 2023, 19, 1171–1190, doi:10.3762/bjoc.19.86

• Guthrie in the 1860s as an attraction between ammonia and molecular iodine [19]. The 20th century saw halogen bonding extended to organohalides such as diiodoacetylene [25][26], and also saw the first X-ray crystallographic evidence of a ‘halogen molecular bridge’ between molecular bromine and 1,4-dioxane

• have been evaluated extensively through both qualitative and quantitative means. Methods of evaluation have included X-ray crystallography and spectroscopy (e.g., microwave, IR, Raman, NMR, NQR), as well as through computational determination of their electrostatic VS,max potentials (Figure 2), their

• positively charged. Halogen-bonded adducts of these have also been observed, which further illustrated the existence and properties of σ-holes in such HVI compounds. For example, I-7-pyr was characterized by X-ray crystallography and by computational methods, where molecular orbital (MO) analysis showed that

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

• Dmitry B. Vinogradov,
• Alexei N. Izmest’ev,
• Angelina N. Kravchenko,
• Yuri A. Strelenko and
• Galina A. Gazieva

Beilstein J. Org. Chem. 2023, 19, 1047–1054, doi:10.3762/bjoc.19.80

• –spin interaction constants of other doublets (2JCH = 1.3–1.5 Hz) indicate the position of the carboxyl (for 4a, red) or carbonyl (for 5a, blue) groups through two bonds relative to the olefinic proton. The structure of compound 5a was additionally confirmed by X-ray structural analysis data (Figure 5

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• solubility of this complex in water. X-ray crystallography of the crystals showed a 1:1 complex of CO2 to α-CD with CO2 bound in the center of the wide, secondary rim of the α-CD cavity (Figure 2). Two of the hydroxymethyl side groups on the primary narrow rim are disordered. The disordering was modeled over

• , placed in an autoclave and pressurized with CO2 gas (pressure 6–20 bar) at 25 °C for 1–17 days. The resulting crystals were collected and filtered by suction filtration. The crystals were left to dry in a desiccator at normal pressure over CaCl2. X-ray analysis. The x-ray crystallographic studies were

• carried out on single crystals, which were coated with mineral oil, mounted on kapton loops, and transferred to the nitrogen cold stream of the diffractometer. The single-crystal X-ray diffraction studies were performed at 100(2) K on a Bruker D8 VENTURE diffractometer equipped with a Mo Kα high